Evaluation of one- and two-equation low-Re turbulence models. Part I - Axisymmetric separating and swirling flows

This first segment of the two-part paper systematically examines several turbulence models in the context of three flows, namely a simple flat-plate turbulent boundary layer, an axisymmetric separating flow, and a swirling flow. The test cases are chosen on the basis of availability of high-quality and detailed experimental data. The tested turbulence models are integrated to solid surfaces and consist of: Rodiʹs two-layer k-(omega) model, Chienʹs low-Reynolds number k-(omega) model, Wilcoxʹs k-(omega) model, Menterʹs two-equation shear-stress-transport model, and the one-equation model of Spalart and Allmaras. The objective of the study is to establish the prediction accuracy of these turbulence models with respect to axisymmetric separating flows, and flows of high streamline curvature. At the same time, the study establishes the minimum spatial resolution requirements for each of these turbulence closures, and identifies the proper low-Mach-number preconditioning and artificial diffusion settings of a Reynolds-averaged Navier-Stokes algorithm for optimum rate of convergence and minimum adverse impact on prediction accuracy